KR100420921B1 - Fluid pressure cylinder - Google Patents

Abstract

Circular pistons and non-circular rods are formed separately as individual parts, and the piston is centered so as to be concentric with the circular bearing holes of the first air bearing, and the rods are non-circular bearing holes of the second air bearing. In a state of centering so as to be concentric with, these pistons and rods are connected to each other with an adhesive to be integrated.

Description

Hydraulic Cylinder {FLUID PRESSURE CYLINDER}

The present invention relates to a fluid pressure cylinder which supports circular pistons and non-circular rods connected to each other so as to be changeable with air bearings on the body block, respectively.

A cylinder system in which a piston and a rod are supported in a floating state by an air bearing installed in a cylinder block is already known, for example, by Japanese Patent Laid-Open No. 11-117912.

The proposed cylinder system supports the piston and the rod by air bearings, so that the sliding resistance of these members can be reduced. However, since the piston and the rod are both circular in shape, these members may rotate at the time of stroke. There is.

However, when the piston and the rod are rotated during the operation, the operation is hindered, so that it is required to be able to prevent the rotation of these members during the stroke.

In order to prevent the rotation of the piston and the rod as described above, a means for preventing the rotation may be simply provided. However, when the piston and the rod are supported in the floating state by the air bearing as described above, the support in the floating state is supported. There is a need for instruments that are not impaired in function. For this purpose, it is simple and appropriate to make the cross section of the rod having a smaller cross-sectional area as compared to the piston, but it is quite difficult to form the circular piston and the non-circular rod integrally in a completely concentric state. It is also difficult to precisely concentrically process an air bearing having a circular bearing surface for supporting the air bearing and a non-circular bearing surface for supporting the rod. Therefore, it is very difficult to concentrically support the circular piston and the non-circular rod as described above with air bearings, and to manufacture them with high precision so that the support in the floating state by the air bearings can be stably performed. This is quite complicated and requires a high precision manufacturing process, which is difficult to manufacture easily at low cost.

An object of the present invention is to provide a hydraulic cylinder which can support a circular piston and a non-circular rod in a concentric manner with high precision by air bearing, and is easy to manufacture and can be manufactured at low cost.

In order to solve the above problems, according to the present invention, a first air bearing having a circular bearing hole, a second air bearing having a non-circular bearing hole, a circular piston movably housed in the circular bearing hole and A fluid pressure cylinder is provided which holds a non-circular rod movably received in the non-circular bearing hole. In addition, the piston and the rod are formed separately as separate parts, and the piston is centered so as to be concentric with the circular bearing hole of the first air bearing, and the rod is concentric with the non-circular bearing hole of the second air bearing. In the centered state, the respective joining surfaces of these pistons and rods are joined together and integrated with each other by an adhesive.

According to the present invention having such a configuration, since the circular piston and the non-circular rod are bonded to each other while maintaining the concentricity with the corresponding air bearing, the piston and the rod are kept concentric with each other. It is not necessary to form integrally in the state, and likewise, the first air bearing having the circular bearing surface and the second air bearing having the non-circular bearing surface need not be precisely concentrically processed. For this reason, the process of each said member is simple, and a cylinder can be manufactured easily at low cost.

According to the specific embodiment of this invention, the said piston is equipped with the accommodating part for accommodating an adhesive agent, and the supply hole for supplying the adhesive agent in this accommodating part to the joint surface of a piston and a rod.

More specifically, the piston has a cylindrical shape with a bottom having a hollow portion therein, wherein the hollow portion is an accommodating portion for the adhesive, and a joining surface for adhering the rod to a bottom portion of the piston; The supply hole which connects the said joining surface and the said hollow part is provided, and one rod is provided with the joining surface for adhering to the joining surface of the said piston at the upper end surface.

In the present invention, preferably, the fluid pressure cylinder is provided with temporary fixing means for temporarily fixing in an unfixed state for centering the piston and the rod.

The temporary fixing means may be a bolt, the bolt being screwed unfixed to the rod through the supply hole for the adhesive in the hollow of the piston.

Preferably, the rod is lightened by forming a plurality of holes for reducing the weight at the center target position.

The rod may further be provided with an air passage for applying a fluid pressure or a vacuum pressure to the tip.

1 is an enlarged end sectional view of an embodiment of a fluid pressure cylinder according to the present invention;

2 is a right side view of the embodiment of FIG. 1, FIG.

3 is a left side view of the same;

4 is a rear view of the same,

5 is a plan view of the same, and

6 is a bottom view of the same.

(Explanation of symbols for the main parts of the drawing)

One … Body block 2. 1st Bearing Mounting Hole

3…. 2nd bearing mounting hole 4... Rod through hole

6. First air bearing 7. cap

8 … Retaining ring 9... Second Air Bearing

12... Piston 13.. road

14. Bolt 16. Air supply port for bearing

18, 19... Discharge port 21. Weight loss hole

25…. Adhesive 26. Hollow part

27. Supply hole

The fluid pressure cylinder shown in FIG. 1 has a rectangular parallelepiped main body block 1. In the main body block 1, circular first bearing mounting holes 2 and second bearing mounting holes 3 having the same inner diameter are concentrically opened from both end faces in the axial direction, and these bearing mounting holes ( In the portion between 2) and (3), a small diameter rod through hole 4 for communicating both bearing mounting holes with each other is provided concentrically with the mounting holes 2 and 3.

The first bearing installation hole 2 is fitted with a cylindrical first air bearing 6 having a circular bearing hole 6a at the center thereof, and a circular shape that blocks the end of the bearing installation hole 2. Cap 7 is fitted in an airtight manner, and they are fixed by a fixing ring 8. In addition, a circular second air bearing 9 having a square bearing hole 9a at its center is fitted into the second bearing mounting hole 3 and fixed by a fixing ring 10.

In addition, in the circular bearing hole 6a of the first air bearing 6, a piston 12 having a bottomed cylindrical body with an open upper end side in FIG. 1 is slidably inserted therein. In the square bearing hole 9a of the two air bearings 9, a rod 13 having a square cross section is slidably inserted as shown in FIG. These pistons 12 and the rod 13 are provided with the flat joint surface 12a provided in the bottom surface of the piston 12 in contact with each other on the flat joint surface 13a provided in the upper surface of the rod 13, and will be described later. In one method, they are connected and integrated with each other by an adhesive applied to these joint surfaces.

The air bearings 6 and 9 are formed circumferentially by a porous air-permeable material, and the bearing surface of the inner surface of the circular bearing hole 6a in the first air bearing 6 is made by reamer processing. The bearing surface of the inner surface of the rectangular bearing hole 9a in the two-air bearing 9 is each finished to a predetermined shape by electric discharge machining. The bearing surfaces of these air bearings 6 and 9 are machined with the aim of being concentric with each other, but need not be concentric with high precision.

In addition, the cross section of the rod 13 is the most preferable for the reason that the machining is relatively easy and there is no action of the uneven load, but the square is most preferred, but is not limited to this, and also the non-circular cross section such as rectangle or regular polygon may be used. It is possible.

2 and 5, the bearing air supply port 16 for supplying the compressed air for bearing, and the axis of the main block 1 in communication with the supply port, are shown in the main body block 1. From through holes 16a extending in parallel to the through holes 16a, from two through holes 16b and 16b (see Fig. 1) and through holes 16b and 16b extending in a direction orthogonal to the through holes 16a. Through-holes 16c are provided which open toward the central position of the outer circumferential surfaces of the respective air bearings 6 and 9. The compressed air supplied to the outer circumferential surfaces of the respective air bearings 6 and 9 through the through hole 16c is ejected uniformly into the bearing holes 6a and 9a through the interior of the porous air bearings 6 and 9. As a result, the piston 12 and the rod 13 are supported in a floating state with little contact with the bearing surface.

The air discharged from the air bearings 6 and 9 to the outside is formed in the main body block 1 from the circumferential grooves 18a and 19a provided on the upper and lower sides of the through hole 16c and the circumferential grooves. It is discharged to the outside from the discharge port 18, 19 for bearing air opened in the main body block 1 through the through-holes 18b and 19b extended in parallel with the axis of 1) (refer FIG. 1 and FIG. 3). . In addition, picking grooves 6b and 9b are formed on the inner surfaces of the bearing holes 6a and 9a in the air bearings 6 and 9 at positions corresponding to the peripheral grooves 18a and 19a, respectively. It is installed.

1 and 6, two air passages 20a and 20b extending in the axial direction and four weight reducing holes 21 are provided with respect to the shaft center of the rod 13. It is formed in the position of symmetry. On the other hand, in the main body block 1, a supply port 24a for supplying compressed air to the air passage 20a and a vacuum pressure port 24b for applying a vacuum pressure to the air passage 20b are opened. In the bearing surface of the second air bearing 9, a groove 22a connecting the supply port 24a and the air passage 20a and a groove 22b connecting the vacuum pressure port 24b and the air passage 20b. ) Are formed separately. These grooves 22a and 22b are formed long in the axial direction of the air bearing, and their length is longer than the stroke of the rod 13, whereby the ports 24a and 24b are independent of the stroke of the rod 13. ) And the air passages 20a and 20b are always in communication so that a fluid pressure or a vacuum pressure can be applied to the front end of the rod 13 through the main body block 1.

Further, by providing a plurality of weight reducing holes 21 in the rod 13 and using the piston 12 as a cylindrical body having a bottom, it is possible to reduce the weight of these members compared to a solid body, so that these driving can be facilitated. .

In addition, the air passages 20a and 20b and the weight reducing holes 21 are not limited to two and four, respectively, as shown in the figure, but are arranged at the shaft center of the rod 13 so that a load does not act on the rod 13. It is preferable that it is symmetrical with respect to.

As shown in FIGS. 1 and 2, the main block 1 has a supply port 23a for descending air for supplying compressed air to a pair of cylinder chambers 15a and 15b partitioned by a piston 12. And a supply port 23b for rising air is provided. Therefore, the piston 12 can be raised and lowered by supply of compressed air from these ports 23a and 23b.

In addition, in order to prevent the need for providing a sealing member in the rod through hole 4 in the main body block 1 and to prevent the sliding resistance from occurring in the rod 13, the lower portion of the rod through hole 4 is provided. The exhaust groove 18c leading to the through hole 18b is opened. The exhaust groove 18c also prevents fluid from the grooves 22a and 22b provided to face the openings of the ports 24a and 24b into the cylinder chamber 12b and thus affects the driving of the piston 12. do.

In the hydraulic cylinder, the piston 12 is inserted into the circular bearing hole 6a of the first air bearing 6 and the rod (9) is formed in the rectangular bearing hole 9a of the second air bearing 9. 13) is inserted, it is very difficult to integrally form the circular piston 12 and the non-circular rod 13 in a completely concentric state in the manufacture of the actual cylinder, It is also difficult to precisely concentrically process the air bearing 6 having the circular bearing hole 6a and the air bearing 9 having the rectangular bearing hole 9a. In order to process each member with high precision and to stably support the piston 12 and the rod 13 in the floating state, a manufacturing process becomes complicated, and therefore, it cannot manufacture easily at low cost.

Therefore, the air bearings 6 and 9 are individually machined into the main body block 1 by processing the bearing surfaces of the respective bearing holes 6a and 9a in a suitable manner without considering concentric accuracy more than necessary. Further, after the piston 12 and the rod 13 are formed separately from each other as separate parts, the piston 12 is kept concentric with the first air bearing 6, and the rod 13 The piston 12 and the rod 13 are fixed to each other with the adhesive agent 25 while being held concentric with the second air bearing 9.

As described above, the piston 12 and the rod 13 are connected to each other. In the example shown in the drawing, the hollow portion 26 of the piston 12 having a cylindrical shape with a bottom is used as an adhesive accommodating portion therein. The adhesive 25 is accommodated therein, and the adhesive 25 is squeezed out between the joining surfaces 12a and 13a from the supply hole 27 provided in the bottom portion of the piston 12 so that these pistons 12 and The rod 13 is bonded. At this time, the piston 12 and the rod 13 are supported by each of the air bearings 6 and 9 by supplying compressed air from the bearing air supply port 16 to each other, and are bonded to each other in that state. .

In addition, the piston 12 and the rod 13 are temporarily fixed to an unfixed state so that relative shifting is possible by temporary fixing means so as not to separate from each other at the time of bonding, and in that state, After adjusting the center, it is preferable to allow the adhesive 25 to penetrate and adhere. In the illustrated embodiment, the temporary fixing means is a bolt 14, which bolt 14 is provided in the hollow portion 26 of the piston 12 through the supply hole 27 and the rod 13. Screwed in unfixed state. In addition, this bolt 14 is also finally fixed to the piston 12 and the rod 13 with an adhesive 25. As a result, since these pistons 12 and the rods 13 are bonded to each other not only through the joint surfaces 12a and 13a but also through the bolts 14, their adhesive strength is significantly increased.

By fixing the piston 12 and the rod 13 to each other with an adhesive 25 in this way, even if the air bearings 6 and 9 mounted in the body block 1 are not completely concentric, By fitting, the piston 12 and the rod 13 can be easily connected and assembled in a state where the supporting function in the floating state is not lost.

In addition, reference numeral 28 in FIG. 1 denotes a damper that is provided on the inner surface of the cap 7 to mitigate an impact at the stroke end of the piston 12, and reference numerals 29 and 30 in FIGS. 4 and 5 denote main body blocks. (1) is a mounting screw hole for installing in a suitable member of an automatic machine or the like.

The hydraulic cylinder having the above configuration alternately supplies compressed air from the supply ports 23a and 23b to the cylinder chambers 12a and 12b, and also from the bearing air supply port 16 to the air bearings 6 and 9. When the compressed air is supplied to the piston, the piston 12 and the rod 13 are supported in a floating state to move up and down. In this case, when the piston 12 is made into a cylindrical body having a bottom and the weight is reduced by means such as providing a plurality of weight reducing holes 21 in the rod 13, the rod 13 is operated at a high frequency. It becomes possible.

In addition, when the supply port 24a for pressurized air provided in the main body block 1 is connected to the compressed air source, and the vacuum pressure port 24b is connected to the vacuum source, an air cylinder provided in the rod 13 is provided. By the furnaces 20a and 20b, the compressed air can be discharged from the tip of the rod 13 or the desired workpiece can be sucked by the rod 13.

According to the present invention described above, the circular piston and the non-circular rod can be concentrically supported by the air bearings with high precision, and the piston and the rod and the air bearings can be processed or the main body block. It is easy to assemble, and the hydraulic cylinder can be manufactured at low cost.

Claims (8)

Circular block formed inside the main body block 1, the first air bearing 6 provided on one side on the axis of the main body block 1, the second air bearing 9 provided on the other side, and the first air bearing 6 Bearing hole 6a, non-circular bearing hole 9a formed in the second air bearing 9, circular piston 12 variably housed in the circular bearing hole 6a, A non-circular rod 13 variably housed in a circular bearing hole 9a, and a mechanism for supplying compressed air into the bearing holes 6a and 9a of each of the air bearings 6 and 9, The piston 12 and the rod 13 are individually formed as separate parts, the piston 12 is centered so as to be concentric with the circular bearing hole 6a of the first air bearing 6, and the rod In the state in which 13 is centered so as to be concentric with the non-circular bearing hole 9a of the second air bearing 9, the respective joining surfaces 12a and 13a are abutted with each other and adhered to each other by the adhesive 25. A fluid pressure cylinder, which is integrated. The method of claim 1, wherein the piston 12 is a receiving portion for accommodating the adhesive 25 and the adhesive 25 in the receiving portion to the joint surface (12a, 13a) of the piston 12 and the rod 13 And a supply hole (27) for supplying the fluid pressure cylinder. The method of claim 2, wherein the piston 12 has a cylindrical shape with a bottom having a hollow portion 26 therein, the hollow portion 26 is a receiving portion for the adhesive 25, A joining surface 12a for adhering the rod 13 to the bottom of the piston 12 and the supply hole 27 connecting the joining surface 12a and the hollow portion 26, one side A hydraulic cylinder, characterized in that the rod (13) has a joining surface (13a) for adhering to a joining surface (12a) of the piston (12) on its upper end surface. 2. A hydraulic cylinder according to claim 1, comprising temporary fixing means for temporarily securing said piston (12) and said rod (13) to an unfixed state for centering. 4. A hydraulic cylinder according to claim 3, comprising temporary fixing means for temporarily securing said piston (12) and said rod (13) to an unfixed state for centering. 6. The temporary fixing means according to claim 5, wherein the temporary fixing means consists of bolts (14), which bolts (14) pass through the supply holes (27) for the adhesive (25) in the hollow (26) of the piston (12). The hydraulic cylinder, characterized in that the screw is attached to the rod (13) in a non-fixed state. The fluid pressure cylinder according to claim 1, wherein the rod (13) is lightened by forming a plurality of weight reducing holes (21) at a center target position to reduce weight. 2. A hydraulic cylinder according to claim 1, characterized in that the rod (13) has air passages (20a, 20b) for exerting a fluid pressure or a vacuum pressure at its distal end.